Current LSIs have been improved in characteristics by miniaturization. However, the miniaturization proceeds into a situation that a gate length of a transistor becomes below 30 nm, thereby bringing about adverse effects of the miniaturization. Hence, an attempt is being made by utilizing, in place of silicon which is conventionally used, another material higher in mobility for a channel to improve the characteristics. For materials therefor, semiconductors such as germanium, InGaAs and so on are floated as candidates, and so-called nanocarbon materials having extremely high mobility, such as graphene, carbon nanotube and so on are also drawing attention.    [Non-Patent Document 1] H. Sugimura et al., Surf. Interf. Anal. 34 (2002) 550.    [Non-Patent Document 2] Kang et al., Nature Nanotechnology 2, 230-236 (2007)